Liquid-storage tank



June 3, 1930. D. D. WILLIAMS ET AL LIQUID STORAGE TANK Filed July '7, 1927 Q ZEZZZZZzJazw 1215M tar ah 8y ATTO R N EY Patented June 3, 1930 PATENT OFFICE UNITED STATES DJ'ALMA DOWN EY WILLIAMS AND HOWARD BRUCE MURPHEY, OF DALLAS, TEXAS, AS- SIGN ORS TO CHICAGO BRIDGE & IRON COMPANY, OE CHICAGO, ILLINOIS, A CORPORA- TION OF ILLINOIS LIQUIDSTORAGE TANK Application filed July .7, 1927. Serial no. 204,024.

This invention relates to liquid storage tanks of the type that comprise a roof which is normally supported by the shell of the tank.

One object of the inventionis to provide a novel means of connecting the roof to the tank shell and permitting vertical movement of that portion of the roof, usually rigidly connected to the tank shell.

Another object is to provide a flexible gastight connection of the roof to the tank proper, to permit of relative vertical motion of the entire roof.

Another object is to provide means of increasing the volume of a tank by vertically raising the roof as a whole by internal pressure.

Another object is to provide a roof that will permit of expansion and contraction of gases, from and above the contents of the tank, without any opening to the outside atmosphere or without piping to additional storage space outside of the tank.

Another object is to provide a flexible connection between a movable roof and a tank shell by means of an annular spring assisted in operation by internal pressure. Another object is to provide a type of gastight construction that will tend to eliminate loss of gaseous yapors by providing additional storage space for their expansion through avertical movement of the entire roof under low pressure. p

Still another object is to provide a mova ble roof that is, from its form, naturally self-draining, in all positions.

This invention also consists in certain other features of construction 'and in the combination and arrangement of the several Figure 1 is a vertical sectional view through a tank constructed in accordance with this invention.

Figure 2 is an enlarged detail sectional.-

desirable internal pressure or requiring a decreased space in the case of contraction otherwise produclng a tendency toward a partial vacuum. This expanding. and con- 4 tracting action is generally known asbreathing of the tank. \f 1 It is the general practice to take care of this change of volume of the gases by passing the same through a pipe leading from the roof of the tank to a point some distance outsideof and away from the tank. The gases passing out through this pipe into the outside atmosphere are lost. sists of the most volatile part of the liquid contents and may be considerable. It is this loss that we propose to eliminate by the use of our invention.

In the drawing 1 indicates the tank and 2 indicates" the roof thereof, said roof normally resting upon the cross beams 3 which are supported on the uprights 4 which are arran ed within the tank at the sides thereof. n angle iron 5 is fastened to the upper edge of the shell and a part of the roof normally rests upon this angle iron, it being understood that the roof is not attached to either the angle iron or 'to'the cross pieces. A flexible member 6 of loop shape is formed with or suitably connected to the periphery of'the roof and the opposite edge of the member isriveted or otherwise fastened-in a gas-tight manner to the shell a distance from'the upper edge thereof, as shown at 7 The member 6 may be connected to the top angle strip, if desired. v

Thus when the mixture of gas and air in This loss conthe top of the tank expands, the roof will be lifted and the flexible member 6 will act as a spring and permit this movement and at the same time prevent the gas escaping from between the roof and the shell. When the pressure lowers the roof will move back upon its supports. 1

A plurality of rods 8 is connected with the roof by the brackets 9 and the threaded lower ends of these rods pass through openings formed in the brackets 10 which are attached to the shell a distance from the upper edge thereof. A nut 11 is placed on so as to prevent dam age to the tank.

If desired, a release and vacuum valve can I be used with the tank for preventing a vacuum or excessive pressure occurring in the top thereof, but as such valves are well known, it is not thought necessary to show them in the drawing.

It is thought from the foregoing description that the advantages and novel features of our invention will be readily apparent.

We desire it to be understood that we may make changes in the construction and in the combination and arrangement of the several parts, provided that such changes fall Within the scope of the appended claims.

What we claim is 1. A storage tank for volatile liquids comprising a shell, a roof with its peripheral marginal portion normally resting on and contacting with the top of said shell, and means for movably connecting said roof to said shell, said connecting means comprising an annular spring loop constituting a pcripheral extension of the roof beyond its point of contactwith the shell and having sufiicient flexibility to, allow vertical move- I ment of the roof upon expansion of gases within the tank.

2. A storage tank for volatile liquids comprising a shell, a roof with its peripheral marginal portion normally resting on and contacting .with'the top of said shell, and means forming a flexible gas tight connection between said roof and shell, said connecting means comprising an annular spring loop forming aperipheral extension of the roof projecting beyond the periphery of the S el and a p ed. t pen to a ow e t al movement of the roof upon expansion of gases within the tank.

3. Means for-forming a flexible gas tight connection between a tank shell and a movable roof comprising an annular spring steel loop connecting the periphery of the roof to the tank shell, the body of said loop projecting beyond the outer periphery of the tank shell to permit the roof to rise vertically and return to its normal position of rest with its peripheral marginal portion upon the top of and contacting with the tank shell.

In testimony whereof we afiix our signatures.

DJ ALMA DOWNEY WILLIAMS.

HOWARD BRUCE MURPHEY. 

